What Does a Gleason Score Mean in Prostate Cancer?

When prostate cancer is found, doctors often talk about something called a Gleason score. This number comes from looking at the cancer cells under a microscope. The pathologist compares them to normal prostate cells and scores how different they look. The more abnormal they appear, the more likely the cancer is to grow and spread.

The score is made of two numbers, each between 1 and 5. The first number is for the pattern seen most in the sample. The second number is for the next most common pattern. These two are added together. So if the main pattern is a 3 and the second is a 4, the score is 7. If the main pattern is a 4 and the second is a 3, the total is also 7, but that 4+3 often means a cancer more likely to grow and spread than 3+4.

A score of 6 is the lowest that is usually reported. This is often called low grade, meaning it tends to grow slowly. A score of 7 is in the middle. Scores of 8, 9, or 10 are high grade and usually more aggressive.

The Gleason score is not the only piece of the puzzle. Doctors also look at PSA levels, how many biopsy samples had cancer, and whether the tumor can be felt or seen on scans. But the Gleason score is one of the most important numbers for deciding what to do next.

For some men, the score means watching the cancer closely with regular tests. For others, it means starting treatment with surgery, radiation, or hormone therapy. Knowing what the number means makes it easier to understand the choices and to talk them over with the doctor.